To find the correct fuse, you need to consult your owner's manual. The manual will have a fuse box diagram showing which fuse controls the power mirrors and what amperage it is. The fuse box is usually located under the hood or inside the passenger compartment (often under the dash).
Without your owner's manual, it's impossible to give you a precise location. The fuse could be labeled something like "Power Mirrors," "Accessories," or a more general label encompassing several circuits.
